Not sure about L52, but it seems for L25 there are plans to expand it indeed. On my last visit, I was talking to the lounge manager in the Ulti space and asked if they had made any progress on plans to install pin-pads on the doors. That's when she told me that they might not do this for now because there are plans to expand the lounge into the space where the general relaxed seating is outside the lounge (close to the escalators) and the area that is next to it. She expected that when that happens, the Ulti space will likely move too and that the pin-pad will come at that point. So, at least as per the L25 staff, there are plans cooking for expansion.

Outside the Ulti space, yeah, the crowding of L25 has gotten really bad over the years. Until they put the Ulti room there, I had stopped going myself too and would only visit the Privium lounges. Only since the Ulti space is there, I've started going to L25 and L52 again.